


Soulmate from Hell

by inarizakis



Category: Haikyuu!!
Genre: Alternate Universe - Angels & Demons, Alternate Universe - Soulmates, Alternate Universe - Supernatural Elements, Fluff, Fluff and Humor, Heaven & Hell, I hope you guys like this, M/M, SakuAtsu, atsumu was kind of agnostic at first, loosely based off from the game obey me, the other hq characters are the demons
Language: English
Status: Completed
Published: 2021-02-15
Updated: 2021-02-15
Packaged: 2021-03-16 11:48:42
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,810
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29453313
Author URL: https://archiveofourown.org/users/inarizakis/pseuds/inarizakis
Summary: In which Miya Atsumu is the student chosen from the mortal world to participate in the one-of-a-kind exchange student program that happens between the three realms, the other two being Heaven and Hell.
Relationships: Miya Atsumu/Sakusa Kiyoomi
Comments: 16
Kudos: 93





	Soulmate from Hell

**Author's Note:**

> Hey. This is my second entry for SakuAtsu Fluff Week Day 2. Hopefully I can make more.
> 
> The plot of the story is loosely based off from the game 'Obey Me.'
> 
> I do not own any of the characters. Hope you enjoy!

Truth be told, Miya Atsumu did not expect to spend his entire school year in the unruly depths of hell – literally.

What happened was bizarre, actually. The student body president had informed him that he needed to attend the meeting that consists of him, the said president, as well as the dean of his college department. Atsumu was nervous, to be honest, beads of sweat forming in his temples as his leather-clad feet tread through the silent hallways of his university. He had no idea why he was being called in the meeting, his brain now racking up several scenarios of flunked examinations and barely-passing departmental examinations, even asking himself if he used up all the absences for his classes.

He knew he wasn’t entirely failing, so what was this about?

Once Atsumu was seated onto the rather comfortable chairs inside the dean’s office, the latter had began speaking. Atsumu had to introduce himself and which department he was from, sweat trickling down the side of his face. An embarrassed laugh ensued from his lips, completely forgetting to bring a handkerchief so he had to resort into wiping using the hems of the sleeve of his uniform.

The dean then greeted him, a kind smile on his face. Atsumu thought that the old man was too kind for someone who was known to expel a lot of his students – wait, what if he was here because he was getting expelled? Holy shit, he better bid goodbye to his family and find a new home to live in. There was no way in hell he was going to live after this.

But with one look at his nervous visage, the dean had to assure him that no, he was not getting expelled, though should rather listen to his story.

Cue the tilting of Atsumu’s head, curiosity now at its peak.

The dean starts to speak, and what comes out of his mouth made Atsumu double take.

Heaven and Hell are _what_ now?

_“Heaven and Hell are real, and the world we live in, the mortal realm, is the middle ground between the two. God is real, Atsumu, and so is the Devil. Angels and demons coexist in all realms, mortals just simply don’t realize it because we don’t have any special senses to recognize a demon or an angel when we see one, but believe me when I say that we exist altogether in this universe as one.”_

What is he saying? Why is the dean giving him a fucked up version of theology class?

Atsumu wasn’t entirely a believer, he had his doubts about whether or not God truly existed, even the domains of heaven and hell because there is no way beings as great and powerful as them existed. But here he was, sitting in front of his dean who was saying that these two _did_ exist and now he’s baffled. Atsumu did not give two fucks if God existed, even the angels and demons. It was weird, made the cogs of his mind spin in wrong rotations.

_“Did you know that these angels, these messengers of God, even the demons, trust us humans from time to time? Right now, as I speak, we are currently in talks of forming a relation between the domains of heaven and hell, so selected humans, even angels and demons, are free to roam the earth as long as they are supervised. This only happens through this one project – an exchange program.”_

What – no. No. No. _NO._ There is no way he’s here because of _that!_

_“The exchange program happens like this. Chosen students of the mortal realm are to go on heaven and hell to experience what it’s like to be a student in the domain you are picked to stay in. Wonderful, isn’t it? And in turn, demons and angels are to roam the earth under the supervision of a guide which will be assigned in their designated realm.”_

_“Congratulations, Miya Atsumu. You have been chosen for the exchange program and are now on your way to Hell!”_

Atsumu was so sure he passed out after that.

And now, six unfortunate months have passed. Atsumu was actually enjoying his time here in Hell, the caliginous domain where there was barely any light out, and the heat was well, just right? It wasn’t a blazing inferno as everyone described it to be, though he was sure it was still true, he just didn’t want to stick around to find out. 

Atsumu had grown accustomed to living here, more specifically in a large, almost castle-like architecture that housed one human and seven demon brothers who were actually siblings. He had a room here, and it wasn’t bad, it was better than the dorm he had in the human world, realm, whatever. The mattress was undeniably soft, quite the opposite of Hell and its residents, to be honest, and the sheets were silk, he was sure that a lot of money was spent on his room to make it presentable for him, to make him comfortable. Atsumu appreciated that, really. 

Though the first few nights were just him silently praying that one of the demon brothers did not accidentally kill him at night. Cue the dark eyebags and the messy mop of blond hair in the morning, to which Lucifer had called him out for several times. He gave the oldest brother the middle finger, forgetting the fact that he was the most powerful demon in this house.

Lucifer Morningstar was not just any demon. He was the strongest, most powerful demon in Hell and was the right hand of the Prince himself. Even if he used to be the angel that everyone had fawned over in the Celestial Realm, the one angel that God favored over anyone else, he still had the same effect to everyone in Hell, though it was in a different way.

Before he was struck down from Heaven alongside his brothers, Lucifer had also lost two of his wings. It was a topic that no one in the house had brought up for centuries already, the pain still somehow raw. Atsumu wouldn’t understand, he wasn’t an angel after all, but considering two of his precious wings were taken away from him, he simply assumed that it was like taking some of his life away.

Here in Hell, Lucifer Morningstar was the Avatar of Pride. He always believed that he was right and he was never wrong, making sure that anyone lesser being, even his brothers, receive punishments for defying him.

Lucifer had that power, and even the Prince of Hell did not question him, always believing him since he was, after all, his right hand. Lucifer isn’t stupid, he is the smartest, and Atsumu knew that the second intelligent demon in this household was the Avatar of Wrath, Satan.

The eldest demon was a bitch to deal with, standing at 6’4” tall, carrying an aura that held class and intimidation. No one could easily come up to him, approach him, and Atsumu himself had difficulty doing that. He had ebony hair that was styled in the perfect curls, the tips of the strands tainted with a fading white. His irises were menacing, black mixed with crimson – staring at them felt like being trapped in an abyss full of red, blood. Lucifer was that, just difficult to approach because he was formal, classy, definitely screamed the strongest demon alive.

But in all honesty? With what happened in the past few months, Atsumu and the brothers have grown closer, especially to Lucifer.

Atsumu had somewhat created pacts with the demons, including Lucifer, and that basically says he’s the most protected human in this whole realm. One strand of hair falls from him and it’s safe to say that one of the brothers will come to his aid. If Lucifer finds out that one of the lesser demons had somehow bullied him in class, the said lesser demons will no longer be present in class, expulsion form in his hand. 

One of the things he had found out as well was that, the brothers did not like to be addressed with the names they were given in the Celestial Realm because they said it reminded them of their old man – God, yes, God is their old man. While it was okay for them to be called like that formally, once you know their preferred names, there is no going back. 

For example, Belphegor, the Avatar of Sloth, is called Rintarou.

Beelzebub, the Avatar of Gluttony, is called Koutaro.

Asmodeus, the Avatar of Lust, is called Tooru.

Satan, the Avatar of Wrath, is called Kei.

Leviathan, the Avatar of Envy, is called Kenma.

Mammon, the Avatar of Greed, is called Satori.

And lastly, Lucifer, the Avatar of Pride, is called Kiyoomi.

Therefore, Atsumu calls the seven powerful brothers by their preferred names, and it was cool because not only because he can call them because of pact privileges, he can call them that because he is considered as family.

Family because he’s been with them through tons of shit, and because he is linked to no other than Kiyoomi himself.

Yeah, who could imagine having a demon as your soulmate? The fact that his soulmate was the strongest and most powerful demon to exist was enough to get him foaming in the mouth. But hey, if this was fate’s doing, then it was alright. Because being with Kiyoomi meant being happy, and Atsumu could not give two fucks whether or not that is the Avatar of Pride, that’s his fucking soulmate right there!

It happened on one fateful night, where he stumbled on the Hall of Paintings because he was bored out of his mind. It was midnight, or so he guesses, Atsumu doesn’t really know because there was barely any light in this literal godforsaken place. His eyes were bleary from getting thirty-minute naps, and he was walking like a zombie, forgetting that he was in a haunted, obviously enchanted home. Atsumu hated it, why couldn’t he be like Rintarou, who was probably sleeping like a rock right now in his room with Koutaro.

And now, here he was, scared out of his wits. Atsumu was literally shaking on his feet right now as he heard laughing. Why did he even go here, when he knew that the painting always gave him goosebumps, the hairs on his skin rising as he felt hundreds of pairs of eyes staring at him.

“Fuck,” he mumbled, looking down on his feet, not being able to walk an inch. “Fuck, okay Atsumu, breathe, breathe, breathe- AH!”

“What are you doing?”

The gloved hand that rested on Atsumu’s shoulder had belonged to Kiyoomi, who was standing tall behind him, figure looming over him with a brooding visage.

Welp, looks like Atsumu’s done for the night. Kiyoomi hated it when they were up until the wee hours of the morning, always prioritizing their attendance in school. At first, Atsumu did not know why Kiyoomi was literally hell-bent on having them school on time, but then again, why should he complain if his brothers would follow him still?

He guessed it was because he’s the eldest, and well, the most powerful. Kiyoomi’s brothers had no choice but to yield. Atsumu too.

“Why are you awake?” Kiyoomi asked, retracting his hand from Atsumu’s shoulder. The latter had turned around to face the demon, crimson irises staring at him curiously, eyebrows furrowed as he expected an answer from him. Atsumu could only laugh nervously, a hand reaching up to his nape, rubbing it. “I couldn’t sleep,” he confessed, shyly looking up to Kiyoomi.

Kiyoomi could only stare at Atsumu’s cowering, anxious figure. He had to admit, he had only noticed that Atsumu was feeling perturbed when he felt uneasiness on his chest. Usually at these times, he was the only one awake among his brothers, always busy tending to papers, reading and signing them. It was tiring, but he was used to it. Kiyoomi could go on days without sleeping, but that doesn’t mean he didn’t need it.

His usual night of being in his private study had been a bit different, maybe because he felt sudden het up feelings. Kiyoomi could only know that it was Atsumu, and because of the pact that they had made with each other, it made Kiyoomi easy to identify where he was.

Now, he found him here, in the Hall of Paintings, looking like a cowardly dog.

The demon sighed this time, eyes closing as he wrapped an arm around his human, nudging him to walk beside him, away from the paintings. “You shouldn’t even be awake right now,” he said quietly. Atsumu hadn’t replied, probably calming his heart down from the gesture. Kiyoomi felt the edges of his brims curve upward – Atsumu was adorable, he knew that. The human had made him.. feel things, and he wasn’t sure if he welcomed it with open arms.

“Sleep in my room tonight.”

And that’s where they were a few minutes later.

Atsumu and Kiyoomi were laying down on the demon’s custom-sized bed. The silk, onyx beddings and cherry that covered his fluffy pillows, the mattress that made him feel like he was on a cloud – it was perfect, Atsumu was sure that he was going to sleep like a baby in here.

They were having a conversation. Quiet laughter ensued from both of their lips, Kiyoomi making animated gestures that you wouldn’t see outside of his space, making Atsumu so entertained – and in love, but he wasn’t going to say that out loud. The two were talking about Atsumu’s antics in the human world, how he often played pranks to his brother, Osamu, and on Kiyoomi’s part, how he visited the realm to visit the witches that Satori had made pacts with – and to pay his debts, but that was unspoken. Both of them knew that the Avatar of Greed had debts, not only to witches.

And now, they were talking about all of the things they have done together. All the trials and tribulations that they have gone through during Atsumu’s stay here in Hell that made him become family to his brothers, and Kiyoomi won’t admit it, but Atsumu was special to him. The human had somehow wormed his way into his black heart, cozying himself in the muscle. But that wasn’t enough, the strange human had also occupied his thoughts, and that made Kiyoomi crazy, because he always found himself thinking about the blond boy.

“You okay?” Atsumu asked quietly, staring at Kiyoomi with those pretty eyes of his.

To Kiyoomi, Atsumu was breathtaking than him. He had always received praises of how he was the most ethereal angel to exist, the one and only Lucifer Morningstar who shone bright. Lucifer Morningstar, he who rivals the light of the sun. Lucifer Morningstar, whose three pairs of ivory wings could become the eighth wonder of the world.

But that wasn’t him, not the most ethereal being to exist, because that title belongs to Atsumu, with his stupid blond hair that was always tousled because he lacked sleep, always tossing and turning on the confines of his bed. Atsumu with his stupid, twinkling eyes that always sparkled with mirth, merriment as he joined forces with Satori to play tricks on his brothers. Atsumu with his stupid, joyous laugh whenever he and Tooru talk about lesser demons making a fool of themselves. Atsumu with his stupid, kissable lips that always turns into a pout when he doesn’t get what he wants. When Kenma doesn’t want to play with him because he’s a normie (though Kenma regrets that, eventually lets Atsumu in the confinements of his room). When Rintarou doesn’t want to nap beside him. When Koutaro doesn’t want to share the last piece of pie with him. When Kei doesn’t want to read him a book.

When Kiyoomi doesn’t let him stay in his study to well, study. Because Atsumu distracts Kiyoomi from his work, and his focus just wavers because he would rather stare at his human than do these stupid paper work assigned by the Prince of Hell.

“Yeah, I’m okay,” Kiyoomi answered the human after a few minutes, staring so boldly.

“Atsumu,” Kiyoomi called out to him, the former looking at him with curious eyes. _Stupid pretty eyes._ “Can I kiss you?”

And Atsumu just nods, heart beating hard in his chest. He’ll finally kiss the demon he actually had feelings for, no longer walking on eggshells after this, he’s so sure with it. The fact that he was going to kiss Kiyoomi, THE Lucifer Morningstar – Prince of Hell excuse him, but he feels like he could ascend in the Celestial Realm.

Kiyoomi draws close, face inches away from Atsumu. Both of them could feel each other’s breath, shaky. This was the next step in their relationship, a kiss to seal the deal. When Kiyoomi finally latches his lips on Atsumu’s, the latter could feel how chapped the skin is, nonetheless, he welcomes the feeling warmly. A hand, Atsumu’s hand, reaches out to cup Kiyoomi’s chiseled jaw, one that could simply cut with how sharp it was. His lips slot perfectly with his, and it was nothing but bliss. Both of them were unmoving, staying still, satisfied and satiated with how they have kissed.

With a single kiss, it felt like everything ignited.

Literally.

Atsumu could feel his insides on fire, eyes closing harder than before. Kiyoomi could feel it too, how Atsumu was in pain, yet it wasn’t the type of pain that would make you hunch down, tears sliding on your cheeks. It wasn’t the gut-wrenching pain he felt when he fell down from Heaven with his brothers. It was the type of pain that turned into pleasure.

Atsumu could feel that his insides were on fire, cold sweat now forming on his skin as his lips continue to be on Kiyoomi’s, his eyes closing harder than before due to the pain he was feeling. Kiyoomi could feel it too, that Atsumu was in pain.

However, it wasn’t the type of pain that was numbing. It wasn’t the type of pain where you would hunch down in defeat, tears slipping onto your cheeks as you cry out for help. It wasn’t the gut-wrenching pain Kiyoomi felt when he and his brothers fought during the Great Celestial War, how he and his brothers fell from Heaven down to Hell.

It was the type of pain that turned into pleasure.

Is it what it seems?

Kiyoomi had a hunch on what it was, and it made him feel excited, exhilarated.

Kiyoomi opened his eyes when he felt the pain subduing, now overcame with pleasure. And now, he waited for Atsumu to open his, hoping and hoping that something good would come out of it.

And it did.

Atsumu let go of his jaw, removing his lips from his as he breathed deeply, heavily. Kiyoomi could see the trickle of sweat falling down from his hairline despite the lack of light in the premise. And now, Atsumu opened his eyes.

Kiyoomi could feel an overwhelming sense of pride taking over his body, his veins, his blood.

What was in front of him right now was still Atsumu, the difference is that, his irises were now the same as his – onyx hues fused with crimson, the same shade as his, and that only signified one thing.

This human in front of him was his soulmate.

Kiyoomi did not believe in soulmates as well as its existence from years ago. He did not see the point of having a significant other even if he was in heaven. Sure, he did see it in his eyes, other angels having lovers of the same kind, either lesser beings or beings that are much more supreme than them, but still, he wasn’t swayed. He wasn’t hateful towards them, just his indifference taking over him. His father – ugh – had told him that a soulmate existed for him.

He never believed in it, just like how Atsumu did not believe in Heaven and Hell at first.

But now, witnessing the whole thing with his eyes, he could not help but believe, agree with his father that his soulmate was indeed in front of him, mirroring the look in his eyes.

Atsumu had slowly smiled, reaching his eyes. Kiyoomi could not help but do the same. His dark heart had slowly gained color, of course, the color was done and reserved for Atsumu, beating solely for him. He knew what this meant, that they were going to be lovers for eternity. To him, it did not matter if Atsumu was human, because he was a powerful being. Kiyoomi would ensure that Atsumu would be safe, existing with him even in his afterlife.

“I love you,” both of them had said the same time.

The day after, all hell broke loose in their humble abode.

“Kiyoomi! What did you do to my human? Why are his eyes red?” was the tirade of questions Satori had yelled as he held Atsumu’s face on the palm of his hands, fingers on his eyelids as he came closer, seeing if the blood-red eyes were truly Atsumu’s. “Are you sure you aren’t lying to me that none of the witches had cursed you?”

Atsumu only shook his head, laughing, removing Satori’s hands from his face. “Satori, you idiot,” Kei called him out from behind, Tooru following him. “That only means one thing, you know.”

“Atsumu’s soulmate is Kiyoomi!” Tooru yelled excitingly, coming near where Satori and Atsumu were.

The Avatar of Pride was horrified. His human was now tainted by his brother? Bound together as soulmates? “Tsum! How could you do that? I was your first, right? I was your guide! How can you do this to me?”

“I’m happy for you, Tsumtsum!” The Avatar of Gluttony, Koutaro, yelled at him from the table, stuffing his face with breakfast, both from his plate and Kiyoomi’s. “Thank you, you big baby,” was Atsumu’s response, the smile never disappearing from his face.

“No, Tsum, I can’t believe you! Replacing me for my stinky brother- what are you doing! Kiyoomi is literally the worst-”

“Are you sure you want to continue that, Satori?”

“Eek!” And the Avatar of Greed could only hide behind the human, who was giddy from seeing his soulmate. “Omi!” Atsumu ran up to the demon, jumping so he could wrap his arms and legs around his figure.

Kiyoomi was not familiar with public displays of affection, red immediately tainting his cheeks as he hid his face in the crook of Atsumu’s neck. He did not want his brother’s teasing him for being easily flustered by a human, nonetheless, but hey, this human was his, his soulmate.

Both Atsumu and Kiyoomi couldn’t have it any less.


End file.
